Di-organo peroxide



Patented Sept. 1 .2, 1950 George H. Denison, In, San Rafael, and John .E.

Hanson, Richmond, Calif., assignors to California Research Corporation, "San Francisco, Calif., a corporation of Delaware Application December 1a, 1948, SeriaiNafiQQfid '13 Claims. (omen- 610) The present invention relates to a method of producing di-organo peroxides and pertains more particularly to a method of producing di-saturated hydrocarbon peroxides.

Various (ii-hydrocarbon peroxides are useful as germicides, fungicides, bleaching agents, polymerization catalysts, etc. In particular, the higher molecular weight peroxides, especially the di-saturated hydrocarbon peroxides, are desirable additives to Diesel fuels for improving'the ignition properties as usually expressed by cetane numbers. 7

Heretofore, various processes have been proposed for obtaining such peroxides. However, the peroxides, especially-the di-saturated hydrocarbon peroxides and the higher molecular weight per rides, have not come into Widespread use'mainly because the prior methods necessarily employed expensive catalysts or expensive and/or difiicultly obtainable reactants. In some processes considerable difliculties are encountered in carrying outthe reaction in large or commercial scale equipment such as metallic vessels. Other disadvantages of the prior art processes are that they result in pooryield's, are hazardous to carry out, or require complicated apparatus.

It is therefore an object of the present invention to provide an improved and novel process for producing di-organo peroxides without the above-mentioned disadvantages.

Another'objectof this invention is to provide a methodof treating hydrocarbon hydroperoxide with acid under certain mild conditions to convert the hydroperoxide to di-hydrocarbon peroxide.

A further object is to provide aprocess-of converting relatively unstable hydrocarbon hydroperoxides obtainedfrom air-blowing saturated hydrocarbons to more stable (ii-hydrocarbon peroxides by acid treatment under mildlconditions.

A parti ular object of this invention is to provide a simple and inexpensive method of producing relatively stable and peroxidic compounds from saturated hydrocarbons.

A special object of thisinvention is to provide a novel process of making (ii-(higher hydrocar' hon) peroxides without the necessityof employexpensive 'materials. I

"These'an'dother objects will bereadily apadvantages inherent in prior art processes.

present process also affords the advantages of high yields of thedesired products, of simple oxides, particularly saturated hydrocarbon hydroperoxides, by treatment with acid under certain controlled conditions, are converted to die hydrocarbon peroxides. 'In this manner, di-hydrocarbon peroxides can be obtained in an efficient and inexpensive manner without-the dis- The operative procedures and of requiring simple apparatus.

An especially effective embodiment of the present invention involves air-blowing lrydro-. carbons to produce hydrocarbon hydroperoxides which are subsequently treated with acid to ob-- tainthe di-hydrocarbon peroxides. A particular feature of the present invention is that the process does not require the use of reactants other than "hydroperoxides and acid, thereby avoiding dependence upon expensive reactants such as alcohols, ketones, aldehydes, hydrogen peroxide and the like. Thus,-the conversion is obtained by contacting the hydroperoxides in pure form,

aside from-preferred admixture with substantially inert diluents, solelywith suitable acids or aqueoussolutions of acids. That is, the present process is carried out under conditions wherein thejhydroperoxides and acid are the only essential reactants. Restated, the acid is the sole effective agentfor the conversion of a hydrocarbon hydroperoxide directly to a .di-hydrocarbon peroxide, 1. e., the auto-condensation of hydroperoxide vto,di-hydrocarbon peroxide is eafect'ed with hydroperoxide and acid as the sole reactants.

Considering the various advantages of the present process, it is an outstanding develop ment and meritorious contribution to 'theart of producing di -hydrocarbon peroxides. The present -pro'cess involves an unexpected and new phenomenon of conversion of hydroperoxides to peroxides by treatment with acid under mild conditions. When such acid conversion is combined with preparation of the hydroperoxides by' l-iquid phaseoxidation' ofhydrocarbons in We have found that hydrocarbon hydroper- 3 accordance with a preferred embodiment of the present invention, it is found that, contrary to the expectations of the prior art, one can eiiiciently and economically prepare di-hydrocarbon peroxides from hydrocarbon by simple operational steps.

To illustrate briefly the present invention, a petroleum distillate composed substantially of paraffins and naphthenes having an average chain length of ten carbon atoms was air-blown in liquid phase to obtain hydroperoxides. This intermediate product was treated with acid to produce di-hydrocarbon peroxides having the formula Ri-QO-R2, wherein the average chain length.

Such (ii-hydrocarbon N solid 4 been generally stated as mild; the conditions may be said to be intermediate between drastic conditions of high temperature and very low temperature below 0 F. That is, the temperature is maintained relatively low, i. e., about room temperature, and the time of contact of the acid and peroxides at the reaction temperature is relatively short.

The treating temperature may be from about 0 F. or better from about F. up to about 150 F. although the higher temperatures are accompanied by considerable decomposition. The reaction is exothermic and usually the temperature is maintained by cooling below about 95 F.

'Ordinarily an intermediate range of F. to

g 85 F. is more suitable, and F. to 80 F. is preaccelerator. Whereas both theliydroperoxide intermediate product as well as the di-hydrocarbon peroxide improve the ignition characteristic of a Diesel fuel (i. e raise'its cetane number), the di-hydrocarbon peroxide product is considerably more stable than the hydroperoxide under storage conditions, particularly as effected by contact with various agents in commercial Diesel fuels.

In accordance with the present invention, hydrocarbon hydroperoxide is converted to di-hydrocarbon peroxide by treatment under mild conditions with aqueous acid having a dissociation constant of greater than 10- With weaker acids the reaction does not proceed to an appreciable extent. The reaction does not evolve hydrogen peroxide or oxygen and evidently is not straight forward; consequently no mechanism is postulated.

The acid is usually employed in amounts ranging from 0.1-1.0, or up to about 1.5 mols of acid per mol of hydroperoxide. The larger amounts will ordinarily be employed with acids of lower concentration. A moi ratio of about 0.3 to 0.5 is preferred for acids of medium concentrations of 60% to 80% in order to obtain high conversion, such as above about 80% to 90%. eral, acid in sufiicient amounts and strength to give a substantial conversion such as 50% or more, will be employed.

Suitable acids (agents capable of neutralizing a base, e. g., caustic) having dissociation constants greater than 10* include the preferred mineral acids such as sulfuric, hydrochloric, phosphoric, nitric and hydrobromic acids. Other acids of sufficient strength include acetyl chloride, oxalic acid, dimethyl sulfate, etc. Sulfuric acid is usually preferred since it gives better yields and is cheaper. The acid is used in at least relatively concentrated aqueous solution; depending somewhat on the nature of the acid used, the concentration of acid preferably ranges from about 50 to 98% in aqueous solution for obtaining high yields,although less desirably lower concentrations such as to 20% may be sometimes used. With concentrations lower than about 50%, conversion is usually incomplete, while the preferred range of acid concentration gives maximum conversion.

, The conditions of the process of converting hydroperoxides to di-hydrocarbon peroxide have In genferrecl.

For best results, the time of contact at reaction temperature should not be unduly prolonged and is usually less than minutes, preferably below 60 minutes. The minimum time is determined by minimum mixing and separation time consistent with maintenance of the low temperatures. Short contact times of the acid phase with the organic phase of from a few seconds up to 3 minutes, which are especially preferred in order to avoid deleterious side reactions, are most conveniently obtained in continuous type operation. The longer contact times are usually necessarily employed in batchwise operation. The higher the temperature the shorter the contact time may be stated as the general rule to follow.

Hydrocarbon hydroperoxides which may be converted to iii-hydrocarbon peroxides in accordance with the present invention are preferably saturated hydrocarbon hydroperoxides, including paraffin, naphthene and mixed paraffin-naphthene hydroperoxides, especially of the secondary or tertiary types. Suitable parafiins from which the hydroperoxide may be derived are normal paraffins such as, for example, butane, pentane, hexane, heptane, octane, nonane, decane, dodecane, tetradecane, hexadecane, etc. and their branched chain isomers such as isobutane, isopentanes, isohexanes, isoheptanes, isooctanes, isodecanes, isododecane, etc. or mixtures thereof. Naphthene hydroperoxides may be derived from cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, and the like. Also, the hydroperoxide derivatives of alkyl substituted naphthenes such as methyl cyclopentane, dimethylcyclopentanes, ethylcyclopentanes, diethylcyclopentanes, trimethylcyclopentanes and the similar substituted cyclohexanes, cycloheptanes, etc. may be employed. The alkyl substituents may also be propyl, isopropyl, butyl, isobutyl, tertiary butyl, etc. In case of the longer alkyl substituents, particularly of the branched chain type, the hydroperoxide group may be attached either on the naphthene ring as in the case of dimethylcyclopentane, for example, or on the alkyl chain, thus forming a naphthene substituted alkyl hydroperoxide. Preferred are the secondary and especially the tertiary hydrocarbon hydroperoxides, i. e., wherein the hydroperoxide group, OOH, is attached to a secondary or tertiary carbon atom, respectively.

While saturated hydroperoxides are ordinarily employed in the present process when a Diesel fuel additive is desired, aliphatic hydroperoxides containing olefinic bonds or aromatic groups can be similarly converted to the (ii-hydrocarbon peroxides in accordance with the process or the pres ent invention. Hydroperoxides derived from olefins such as octenes', decene, 2 ethylhexeiie, etc., may thus be used. Hydroperoxides' of isobutylene, alkyl benzenes', such as toluene, xylene, ethyl ben- 'zene, isobutyl benzene, octyl benzenes, cetyl benzenes, etc, and similar substituted naphthalenes may be employed. 1 t

In addition to purely hydrocarbon peroxides there may he used hydrocarbon peroxides which are substituted to such minor extent that the substituents do not appreciably affect the essential hydrocarbon character of the hydroperoxide. Thus, there may be employed in the present invention organo hydroperoxides, wherein the organo radical consists essentially of a hydrocar bon group as the main character of such organo radical, without excluding the presence of minor substituents such. as chioro, promo, nitro, etc. which are merely inert or which do not change the essential hydrocarbon character or the organo radical. For example, chloro-tertiarybutyl hydroperoxi'de, bromo tertiary-buty1 hydroperoxide, and analogous hydroperoxides derived from 1,ldibromo-2-methyl propane, 1- chloro l-bromo-2-methyl propane, 1,2-dichloro- 2,3 dimethyl butane,- 1-fluoro-2-methyl propane, l fiuoro 3 methyl butane, l-chloro-Z-phenyl propane, l-bromo-2-benzyl propane, 1-chloro 2- naphthyl propane, l-chloro-il cyclohexyl propane, 1,1 dich1oropheny1-2 ,2,2 trichloroethane, and the like as well as their homologues maybe ployed. Y

' The present process is applicable to the individual hydroperoxides or mixtures thereof. Suitable mixtures may contain, for example, several hydroperoxides of any one or more of the various types such as paraliin, naphthene", mixed parafiin-naphthene and aromatic hydroperoxides. Suitable hydroperoxid'es may be derived from various petroleum hydrocarbon fractions, such as straight-run gasolines which may contain both paraifins and naphthenes, other petroleum distillates, e. g., fractions having AS'I M 50% boiling point within the range 200 to 450 F. or 325 to 650 F., etc. I

While an individual hydroperoxide alone may be readily converted to a di-hydrocarbn peroxide in accordance with the present invention, the more active pure hydroperoxides, especially those of lower molecular Weight, can be diluted with a substantially inert solvent, such as a light solvent such as pentane, hexane, etc, or light oil, such as pale oil, kerosene, etc, in order to control more readily the reaction. Ordinarily, a 50%, preferably 5-'25%, solution of hydroperoxldes in a diluent is employed in order to obtain easily conftrollable acid-treating conditions and/or high conversion.

The present process is especially suited for preparing stable 'cetane improving Diesel fuel additives by treating higher molecular weight hydrocarbon hydroperoxides having at least 8 carbon atoms and up to about 18 carbon atoms in the hydrocarbon chain.

The hydroperoxides. constituting the feed stock for the present process may generally be .m'eparedv in any suitable manner. The process of obtaining hydroperoxides by treating an alcohol with hydrogen peroxide and anhydrous sodium sulphate is described in Patent No. 2,223,807; In accord- 6 ante with Patent No. 2,383,919,'tertiary alkyl hydroperoxides may be recovered from the reaction product of vapor phase oxidation of saturated aliphati hydrocarbons having a tertiary carbon atomwith an oxygen-containing gas and in the presence of hydrogen bromide. Patent No. 2,430,864 discloses a method of obtaining pure naphthene, hydroperoxide's by liquid phase oxidation of naphthenes. Schultz et al. Patents 2,317,968 and 2,365,220 disclose a more general method of liquid phase oxidation of petroleum distillates containing, for example, both. paraflins and. naphthenes, to produce oxygenated hydrocarbons, in which the chemically reactive oxygen content is expressed in terms of oxygen factor.

In such oxidation processes it is desirable to purify the feed material by removal of oxidation inhibitors and other materials which may have deleterious action on hydroperoxides, e. g., sulfurand' nitrogen-compounds, many naturally occurring sulfur, nitrogen, oxygen-containing compounds.

A particularly advantageous feature of the present invention resides in preparing di-hydrocarbon peroxides from hydrocarbons, especially saturated hydrocarbons. Such process involves liquid. phase oxidation of suitable hydrocarbons with an oxygen-containing gas under controlled conditions and thereafter subjecting the resultant hydroperoxidc-containing product to acid treatment under certain mild treating conditions toproduce (ii-hydrocarbon peroxides. This present process constitutes an improvement over the Schultz et a1. process of the aforementioned Patents 2,317,968 and 2,365,220. Therebyfthe octane improving hydroperoxide containing product of Schultz et a1. is converted to superior octane improving di hydrocarbon peroxides, which are more stable in storage upon admixture with certain types of base fuels and which are substantially less corrosive. In general, the dihydrocarbon peroxides produced from hydrooarbons in this manner are low in cost, permanent and stable in storage, and without adverse qualities from the standpoint of marketability, and where used to promote ignition, of consistently high ignition quality.

Where it is desired to produce an additive for improving the ignition qualities, 1. e., cetane number, of Diesel fuels and the like, the present improvement process is particularly applicable either in conjunction with the process of Patent N 0. 2,365,220, whereincharg-ing stocks corresponding to an ASTM 50% boiling point within the range 325 to 650 F. are employed, or Patent No. 2,317,968, wherein the charging stock boils within the range 200 to 450 F. For this purpose the hydrocarbon oil to be oxidized should be free from large proportions of aromatic ring structures and should contain a group of relatively volatile hydroca'rbons. While straight-run petroleum distillates are often used to advantage as initial materials, fractions containing large percentages of branched chain compounds are usually preferred. Ordinarily, petroleum fractions should be acidtreated or selectively solvent refined before oxidation for optimum results. Oils containing high proportions of aromatic rings are less capable of yielding octane-improving compounds than are oils of high parafhnioity, although the treatment ofoils of'higharomatic content with relatively strong sulfuric acid or an equivalent chemical reagent for their extraction with liquid solvents such as liquid sulfur dioxide, phenol, aniline, furfural, nitrobenzene and the like in removing aromatic components for reducing their concentration, sufiices to improve their amenability to treatment in accordance with the invention.

A convenient means of following the course of the oxidation process resides in the oxygen factor determination. The oxygen factor" of an oil is determined as follows: A 2 to 10 ml. sample of oil at approximately 68 F. is accurately pipetted into a 250 ml. glass stoppered flask. 20 ml. of a mixture consisting of 60 volume per cent of C. P. glacial acetic acid and 40 volume per cent of chloroform are added to the oil, followed by 2.0 ml. of a saturated aqueous solution of potassium iodide. The mixture is shaken vigorously for 3 minutes and then diluted with about 50 ml. of distilled water. The liberated iodine is titrated with 0.1 normal standardized sodium thiosulfate solution, adding starch indicator just before the end point is reached. Considerable shaking is necessary near the end of the titration. Oxygen factor=(titer in ml. norniality of thiosulfatex 1120) (volume of sample in ml.)

The oxidation step of the process is preferably carried out within the temperature range of 250 F. to 350 F. Preferably, the oxidation is carried out with the aid of a small amount of feed stock from the previous run. An amount of feed stock between about 0.5% and 5% is usually desired. With the petroleum distillates referred to hereinabove and mentioned in the Schultz et al. patents, atmospheric pressure is normally. suiiicient; with other feeds, especially lower boiling hydrocarbons, superatmospheric pressures, e. g., up to 350-400 atmospheres, preferably below 100 atmos'pheres', may be employed. The oxidation with an oxygen-containing gas such as air is continued for a time not materially longer than is necessary to give an oil of maximum oxygen factor obtainable, and also to prevent undue formation" of undesirable side reaction products. In general the oxidation step is regulated to produce an oxygen factor of at least 250 and preferably above 800 and aneutralization number of not morethan 15. Itis usually most desirable for best conversion of hydroperoxides to employ an excess of oxygen-containing gas. For example, sufficient air is employed so that the eiiiuent gas is not completely deoxygenated. For increased yield it is sometimes desirable to carry out the oxidation in the presence of abasically reacting agent such as alkaline earth metals or compounds of alkaline earth metals, alkali metals, iron group metals and metals of the right-hand column of group II of the periodic table which form salts with acids produced'during the oxidation; such agents, e.'g., alkali metal carbonates and bicarbonates or dilute aqueous solutions of alkali metal hydroxides are used in sufficient amount to prevent accumulation of appreciable amounts of acids which tend to promote deleterious side reactions. Neutralization can likewise be effected in a separate stream withdrawn from the oxidation chamber and returned thereto after treatment. The partially oxidized oil should not be allowed to remain at or near oxidizing temperature for any considerable length of time subsequent to the attainment of the desired oxygen factor due to the secondary reactions which continue at the expense of the desired product. It is therefore of importance to quickly cool the oil as, for example, by quenching with water to a temperature below-that at which secondary reactions take place rapidly, namely, to a temperature below about 250 F. and preferably as low as 100 F.

It is sometimes desirable to wash this partially oxidized oil with dilute caustic solution (such as up to 5% caustic) to remove acidic substances and salts or soaps of organic acids before proceeding with the subsequent treatment. A 5% aqueous caustic solution in an amount equivalent to about that theoretically required to effect neutralization is preferably used. A materially stronger caustic solution tends to destroy or remove the desired hydroperoxides, as does a substantial excess of the caustic. In most cases it is advantageous to dispense with the caustic wash and proceed with the subsequent treatment.

Further complete discussions of the steps of partial oxidation, quenching and caustic washing a chosen feed stock as well as analytical methods for the determination of oxygen factor and neutralization number are given in U. S. Patents Nos. 2,365,220 and 2,317,968 to Schultz et al.

It is ordinarily not advantageous to concentrate the hydroperoxides, nuch as obtained from the aforementioned oxidation process, before the subsequent acid treatment. Such concentration is sometimes desirable and may be effected by fractional distillation, preferably under reduced pressure, by solvent extraction, such as with 90% aqueous methanol or by chemical means or combinations of such methods. As chemical means the hydroperoxides may be extracted or precipitated as salts by treatment with an alkali or basic metal compounds, such as alkaline earth metal hydroxides or carbonates; after separation from the mixture the salt may be dissolved in water and acidified with dilute acid to reform the hydroperoxide.

Referring now to the acid treating step: The preferred feed therefor is obtained by the abovedescribed liquid phase oxidation of substantially saturated hydrocarbons. Such unconcentrated feed mixture usually has a hydroperoxide content of about 8 to 15%, although hydrocarbon solutions resulting from oxidation or from dissolution of hydroperoxides in hydrocarbons may contain greater or smaller amounts of hydroperoxides such as from 5 to 25% and be effectively treated by acid. As noted above, the hydroperoxides are preferably in dilute solutions for the acid treating step. The illustrative feed stock containing 8 to 15% hydroperoxides (having an average of ten carbon atoms) will have an oxygen factor rangin from 800 to 1500. To cause conversion of the hydroperoxides to dihydrocarbon peroxides in such a feed stock, it has been found in general that treatment with between 0.1 and 0.75 pound of 50% to 98% acid, e. g., sulfuric acid, per gallon of the partially oxidized unconcentrated feed stock is most satisfactory. It has further been found that under the mild Operating conditions, such as at a temperature of 60 to F., etc., as hereinabove set forth, a treatment with about A; to pound of 75% sulfuric acid per gallon of the above feed gives optimum results. While for the purpose of obtaining optimum short reaction time the more concentrated acid and/or higher acid to hydroperoxide are used, lower ratios or acid of the lower concentrations may be employed. Thus, for conversions of above about 50%, the mol ratio of acid to hydroperoxide may range from 0.1 to 1.0, or up to 1.5 mols of acid per mol of hydroperoxide. For example, the following table presents data showing the results of treating a feed stock, such as referred to above, having an oxygen factor of 1070 and hydroperoxide content of about or about 2.2 mols per gallon, the hydroperoxides having an average of about ten carbon atoms. The reaction temperature was maintained at about 70 F. and sulfuric acid of 75% concentration was used at the indicated ratios.

TABLE I Amount of M01 Acid] Oxygen Acid (LbsJ Mol hydro- Factor of gal. of feed peroxide Product stock) -minutes and'which may be separated and disposed of, is practically eliminated by limiting the contact time to less than about 3 minutes.-

For control purposes it has been ascertained that when the temperature is controlled as above indicated the reduction in the value of the oxygen factor serves as a criterion for the maintenance and attainment of optimum conditions for the acid treatment. In general it has been observed that in treating feed stocks obtained from liquid phase oxidation it is not advisable to attempt to acid treat to extinction of oxygen factor, since the additional treatment necessary to chemically efiect the last portions of oxygen factor responsive compounds tends to cause decomposition of the peroxides. Hence, conditions of acid treatment are preferably adjusted to give a reduction to about 10 to 20% of the original oxygen factor value. containing 8% hydroperoxides having an average of ten carbon atoms in the molecule, such conversion yields a reaction product containing about 5% to 6 di-hydrocarbon peroxide.

Batchwise acid treatment can be applied to hydroperoxide-containing mixtures such as the above-mentioned partially oxygenated oil. It has been found that the temperature may be readily controlled to the desired value, for example, by

adding the total sulfuric acid employed in several dumps with a cold water wash between each dump to counteract the heat evolved in the reaction. When treating the above-mentio-ned oxygenated oil feed stock the pound per gallon of sulfuric-acid was conveniently added in four dumps together with the intermediate cold water washes for cooling. Instead of using cold water washes for cooling, external cooling and/or refrigerating coils inserted into the mixing chambcr may be employed to control the temperature. The acid treated oil is preferably Washed with water after the last acid treatment to remove excess acid, is then Washed with dilute caustic until neutral, and finally with water until salt and caustic-free. It is preferable to use a 10% For example, in treating. a feed stock 10 excess of 5% aqueous caustic over that required for neutralization.

Mixing of the acid and hydroperoxide containing feed followed by immediate separation in a continuous manner has been found preferable in order to obtain minimum contact time. Various continuous mixers, such as turbomixers, mixing nozzles, etc., may be employed. An efiicient separator or series of separators of various designs may be used, followed by continuous water wash of the non-aqueous peroxide phase. External refrigeration may be applied to the mixer itself and/or to the feed streams to the mixer as well as the mixed eiiiuent stream in order to maintain the desired temperature preferably at 60 to F. The water-washed product is then caustic treated, either continuously or batchwlse, as noted hereinabove. A particularly effective procedure for obtaining optimum short contact time and high yields without appreciable deleterious side reactions involves the steps of mixing the hydroperoxide and acid by means of a spray nozzle, then immediately passing the resultant mixture to 'a settler, from which the acid layer is continually drawn off. With immediate dilution of the withdrawn acid layer with water, sludge formation is substantially completely prevented. With long "intervals before dilution, sludge tends to be formed in the acid. The treated upper layer as immediately separated from the acid is appreciably reduced in oxygen factor. Upon standing out of contact with the acid layer for a short time, such as 5-20 minutes, preferably about 10 minutes, the oxygen factor of the separated upper layer drops further to the desired low value, showing completion of the reaction. Then the product is waterand causticwashed.

Where the hydroperoxides have been concentrated, such asby fractional distillation of the liquid phase oxidationproduct to yield a mixture having an increased oxygen factor of at least 1000, preferably about 3000 to 7000, or up to 15,000, the concentratev may be acid-treated as described above, except a correspondingly greater amount of acid per gallon of feed stock is used to obtain the hereinbefore-indicated proper acidhydroperoxide ratio and to give a final product having an oxygen factor not greater than about 20% 0f the oxygen factor of the concentrate.

Where the hydroperoxides are separated from the unreacted hydrocarbons by chemical means, i e.',' by precipitation as salts, the reformation of thehydroper'oxide and conversion to di-hydrocarbon peroxides can becarried out in one operation by employing sufiicientacid to form the hydroperoxide from the salt plus enough acid for the desired conversion of hydroperoxide to ell-hydrocarbon peroxide.

For some purposes, the (ii-hydrocarbon peroxide containing product thus obtained in the above-described batchwise or continuous acidtreating methods is ready for use; for example, when the oil feed stock chosen for oxidation is suitable for use as a Diesel fuel, the product is now an improved Diesel fuel. If, however, the oil feed stock selected is not a suitable Diesel fuel as, for instance, by reason of its low boiling range or if the object is to produce a blending agent which may be added to 'a Diesel fuel stock to increase the octane number, the acid-treated oxygenated oil may be added to a base stock in anamount to produce a fuel having the desired octane number. i

F It isfrequently desirable, however, to obtain the (ii-hydrocarbon peroxides in substantially pure or more concentrated form, and in such cases the di-hydrocarbon peroxides may be concentrated by distillation or other suitable means, for example, by solvent extraction or adsorption fractionation or by combinations of such methods. The hydrocarbonaceous material separated from the di-hydrocarbon peroxides and concentrates thereof may be recirculated to the air-blowing step, preferably after subjecting it to acid treatment as is the original feed stock, in order to render it'more suitable for conversion to hydroperoxides. In many cases it will be found preferable to concentrate by distillation and this method .is illustrated and more fully described below. Ordinarily, it is preferable to concentrate the di-hydrocarbon peroxides by removing the relatively lower-boiling material from the mixture. The portion removed may contain substantially only inert hydrocarbons which may be recycled after suitable treatment to the oxidation step of .the process or maybe otherwise utilized or discarded.- The distillation residue may vary be tween about and 40% of the original charge depending on conditions of previous treatment and expected uses; for example, where the undistilled product contains about 5-10% peroxides, distillation may be carried out until only about 20% of the original volume remains in the still. The bottoms remaining in the still may contain the di-hydrocarbon peroxides in amounts from about 20-70% or more, usually of the order of 40% or in some cases to substantially pure peroxides. For example, when the acid treatment described above and the concentration step of the process is applied to a hydroperoxide feed derived from liquid-phase oxidation of a hydrocarbon fraction havingan average of ten carbon atoms per molecule, the resultant concentrated peroxide-containing oil will have an oxygen factor of not greater than 600 and preferably less than 300. It has been found that concentration by fractional distillation may best be carried out at a subatmospheric pressure, such as -30mm. of mercury or lower. Satisfactory pressures are determined by the properties of the charging stock being concentrated. In general, a higher pressure is'usable with a lighter charging stock. The temperature desirably is maintained below 350 F., preferably below 250 F., and especially of the order of 200 F.

Solvent extraction may be used in place of fractional distillation or following distillation, in

order to further concentrate the peroxides. Al-

though a variety of extraction solvents may be used, including relatively concentrated aqueous aliphatic alcohols such as isopropyl alcohol etc., polyhydroxy alcohols such as ethylene glycol, glycerol, etc., ethers and esters of the latter class such as diethylene glycol, monomethyl ether, glycol diacetate, etc., pyridine and its homologues, water-soluble ketones, such as acetone, it is preferable to use aqueous methanol as the extraction agent. The peroxides may be extracted from the mixture with 75 to 95%, preferably about 90%, aqueous methanol by continuous or batchwise extraction. Thereafter, the extract phase may be diluted with water to free the peroxides as an oily layer. The separation of the peroxides from the aqueous alcoholic extract phase may also be carried out by distillation, preferably under reduced pressures, to vaporize thealcohol and water. If desired, the extract so obtained may be subjected to distillation in 12 order to further concentrate the di-hydroc'arbon peroxides.

As a final step, the product may be washed with a small amount of caustic, such as 5-40% caustic, for example 1 to 2% of 15% caustic, and then water washed. In case the peroxide concentrate is relatively high in acid content, it is most desirable, in addition, to water wash before the caustic wash. H

Referring to the drawing, one preferred embodiment of the present invention is carried out as follows: A suitable feed, such as a petroleum fraction containing predominantly parafiins and naphthenes" and boiling in the rangeof 308 to 366 F. is introduced via line I through pump 2 and line 3 into an oxidizing chamber, such as oxidizer 4, for converting the hydrocarbons to hydroperoxides; air or other oxidizing agent is introducedinto oxidizer 4 through line 5. Ordinarily, batchwise oxidation is employed, although continuous operation with or without recycle of the effluent oxygenated hydrocarbon may be used. Distributing means (not shown) may be provided within oxidizer 4 to provide eflicient contact between the air and hydrocarbons. At the start of the oxidation, the oxidizer and the feed materials are heated to oxidizing temperature. After heating, say, for the first hour of the operation, cooling is employed to control the exothermic reaction. The rate of introduction of air or other suitable means, such as internal or external coolers, may be used to control the temperature within the oxidizer at the desired temperature of about-300 F. Par tially deoxygenated gas, together with entrained liquid or gaseous hydrocarbon and reaction products leave the oxidizer 4 via line 6 through a cooling and condensing unit 1 and enter separator 8 where the mixture is separated, the water layer formed therein being disposed of separately. Gas and uncondensed vapors are removed via line 9. The hydrocarbonaceous liquid is withdrawn from condensing unit 8 through line I0 and pump II and recirculated to oxidizer 4 via line 3.

When, in batchwise operation, the hydrocarbon has been treated to the degree desired, as measured by the oxygen factor and neutralization number of samples withdrawn at suitable intervals or other control means, the oxygenated hydrocarbons are withdrawn from oxidizer 4 by means of line l2 and pump [3. Preferably the oxidation product withdrawn from oxidizer 4 is rapidly cooled in cooling means M to about F. and then may be passed to an intermediate surge or storage tank I5.

In continuous type operation, part of the oxygenated hydrocarbons may be recirculated through lines it and 3 to oxidizer 4 and it is sometimes advantageous to recirculate the main body of hydrocarbons in oxidizer 4 by passing hydrocarbons via a closed circuit including lines I 2, l6 and 3 and pump 13. In some instances, two or more oxidizers in series may be substituted for oxidizer 4, in which case the hydrocarbons are circulated from the first oxidizer to subsequent oxidizers and are withdrawn from the last oxidizer in the series.

The hydroperoxide intermediate is then taken from surge or storage tank l5 and passed via line I! and pump l8 through cooler l9. With addition of metered amounts of acid introduced through line 20 and pump 2| the hydroperoxidecontaining mixture passes through line 22 and a mixing nozzle 23 or other suitable mixing device wherein eflicient contact between the acid and hydroperoxide is obtained, causing .the conversion of the hydroperoxide to (ii-hydrocarbon peroxide. The reaction mixture passes through cooling means .24 which, withcooler l9, m-ay"form part of a relatively thigh capacity refrigeration system to maintain the desired temperature, such as 80 F.

The acid-peroxidemixture is then introduced into a suitable separator system, suchas a gravity separator 25, wherefrom the acid .and peroxide-containing mixture are separately 26.15- charged through lines to and 21,, respectively. Preferably the acid is separatedtrom the p.er oxide-containing mixture as soonraslpossiblesafter contact. Thence I the peroxide-containing mixture passes through a surgedrum 28,, .line 29 and pump 30 to a treating unit comprisingyior example, a lower section. d! :for caustic washlaznd an upper section 32 for subsequent water wash. Caustic such as 20 Beqaqueous caustic Bis introduced into lower section 3| through line .33 and discharged as spent caustic through line 34. The

caustic-washed peroxides and hydrocarbons pass from section 3.! through line 35 to water-wash section 32 having water inlet line 36 and water outlet line 31. p

' The caustic land wate1'"-washed pernxideecontaming mixture flows through efiluent .line 3.8 through heating means 39 which may be a heat exchanger .oi" the like, to a. fractional distillation column, such .as vacuum fiashtower til. Therein the relatiyely volatileflinert components .consisn primarily of .unoxidixed hydrocarbons awe taken oyerhcad via line a through condenser as into separator dm m {it and thence through :line M, ump idand value-controlledlines ts and lit to teed line .l .-i-cr recirculation through the sysandfurthcr-cxi 1atiom or'are removed from the system via yalve contm edli-ne as. If desired, the recirculated. geuerhcad hydrocanbonaw cecus material may he acid treated as is the prim feedstock. Part of tie ouerheadccndensate is returned reflux tortowe'r cc Maine-soon trolled line 39. suitableauacuutm generating f .:,The drawing of the above-described cmbcdi omits sake'of simplicity such auxiliaries valves, flow, level .and'pressune controllers, metering devices, temperature regulators and the like, aswill be readily supplied by one skilled the art. i i

hydroperoxides are not prepared from liquid phase oxidation ofiiydrocarhcns such as oxidizer it, the illustrated equipment in the line .of flow prior to the surge or storage tank it: be omitted, and hydrcperox despreferably solution in an inert solvent, such as liquid hydrocarbons, are introduced into the systemstarting with line ll and .ptumplfi. i 1

As illustrative of the present invention the 01 lowing examples are given:

Example 1.-l.6.5 c. c. of technical dimethyl cyclopentyl hydroperoxide about 85 purity and having an oxygen factor of 11,717.09) was diluted to 165 cc. with il-piintaneand the resultant solution (an oxy en factor of "1084) treated with ml25'ilbt igal. of (5% sulfuric acid at 40-50 F. over anjhom period. After separating from the aqueous acid phase, the upper oily layer was water Washed and neutralized with sodium bicarbonate. lTpon evaporating off the n-pentane, 13.6 c. c. of product was recovered, which had an oxygen factor of 4370. At 0.5% concentration in an untreated Diesel fuel having a cetane number of about 41, the product caused an increase of an average .of 12.2 cetane numbers. .At the same concentration in the same fuel, technical dimethyl cyclopentyl hydroperoxide of about 60% purity gave only a cetane numberincrease of 6.5. Example 2.-- -To 100 c. o. of 88.7 tertiary butyl hydroperoxide, there was slowly addedpver a two-hour period c. c. of 65% sulfuric acid while maintaining the temperature below about 7 C. After allowing the mixture to stand overnight, an additional 50 c. c. of 75% sulfuric acid was added in 80 minutes time at a temperature below 0 C. Thereafter with the reaction vessel placed in a cold water bath to start, the tempera ture was permi-ttedto warm to room temperature. After separation of phases, the upper layer was washed free .of hydroperoxide with several 10 c. 0. portions of 40% caustic. After a final water wash, c. c. of di-l(.tertiary butyl) peroxide was obtained. This product was determined to 'be fairly pure byii'ts lack of oxygen factor and measurement of density, boiling point and refractive index. 7

Example 3.--A number of individual hydrocarbons of approximately 98% or better purity were first oxygenated byplacing a sample of each hydrocarbon ina vessel fitted with an air inlet, a sampling device, a water trap, and a reflux condenser. This apparatus was immersed in a constant temperature .oil bath maintained at per- .oxidation temperature. Aftersufiicienttime for the contents to reach the bath temperature, air was passed through the hydrocarbon via .a dis tributing plate in the bottom of the oxidizer vessel. Samples were withdrawn from the main body of the hydrocarbon at periodic intervals. The oxygen factor (indicating the hydroperoxide content) of the sample and acid content were determined. When the oxygen factor reached a maximum or shortly thereafter, the stock was removed from the apparatus, cooled and neutralized with 50% by Volume of 5% sodium bicarbonate to remove acids. The peroxidized .material was then added in 2.5% and 10% concentrations to a. Diesel fuel base (derived from waxy California crude) and the cetane number of the blend determined. The results obtained in this manner .are given in the Table H below, wherein the peak oxygen factor is that obtained by determination on withdrawn samples whereas the blending oxygen factor is the final oxygen fac tor of the product prior to blending. (The latter value is usually lower since the neutralization reduces the peroxide content approximately 10% and air blowing was generally not stopped until the peak had been passed, resulting in a lower peroxide content.) The octane number increase for the unperoxidized material was obtained in order to show the true effect of the peroxide since only 5 to 20% of the'unconcentrated blown material was peroxides; hence cetane number in crease was corrected in accordance with such blanks. The relative efiectiveness of the different hydroperoxides is given as the increase in octane number per 1000 oxygen factor, in order to bring the effectiveness of the peroxides to a common basis.

TABLE II Results of peroxzdation of pure hydrocarbons Cetane Number Increase Relative Ei- Peroxi- Blend: fectiveness, Compound ggo g i 52 Pei-oxidized ggg Corrected SON/1000 n-Decane 275 719 590 8. 6 15. 7 +0. +3. 1 8. 1 12. 6 13. 8 21. 3 n-Dodecane- 300 529 302 3. 2 10. 6 1 (10. 6) 1 (33. 1) Octene-1. 240 1, 142 902 7. 5 14. 6 +0. 1 +0. 4 7. 4 14. 2 8. 2 16. 7 Decene-l- 250 849 614 5. 1 10. l +0.1 +0.6 5.0 9. 5 8.2 15. 4 Ethylcyclohexane 265 1 l, 484 1, 250 7. 0 13. 3 O. 6 -1. 3 7. 6 14. 6 6. 1 l1. 7 Iso-Propylcyolohexane" 300 1, 422 956 5.6 12. 0 0. 7 l. 5 6. 3 13. 5 6. 6 14. l thylbenzeneunsnu- 265 a 2,050 1,868 5. 5 8.3 -1.4 3.5 6. 9 11.8 3.7 6.3 o-Xylcne. z 275 Z 624 564 1. 5 l. 7 O. 6 2. 6 2. 1 4. 3 3. 7 7. 6 Xylene 275 86 66 0. 9 3. 2 l. 2 2. 9 0. 3 0. 3 4. 8 so-Propylbenzen 300 215 211 0. 2 0. 6 2. 9 3. 1 l4. 7 p-Methyl-4-isopropy 911 275 3, 685 3, 170 6. 7 11.3 l. 4 3. 3 8. 1 14. 6 2. 6 4. 6 Tech. Trimethylbenzenes- 300 2, 340 1, 915 5. 3 8. 3 O. 9 4. 5 6. 2 12. 8 3. 2 6. 7 Tech. Diethylbenzencs- 300 384 311 0. 2 0.0 O. 9 3. 2 0. 7 3. 2 2. 3 Tech. Monoamylbenzenes. 300 492 370 2. 7 3. 4 -0. 8 3. 3 3. 5 6. 7 9.5 18.1 Petroleum distillate 300 1, 320 784 6. 7 11.6 O. 8 L 7 7. 5 l3. 3 9.6 16.9 Do. 300 800 5. 2 10. 2 0. 8 1. 7 6.0 11.9 7. 5 14. 9

l N orn: Uncorrected for the eflectiveness of the unoxidized hydrocarbon.

l N one: These compounds did not reach a peak at the end of 40 hours.

3 NOTE: This distillate had a hydrocarbon analysis of 50% paraffins, 48% naphthenes and 2% aromatics; an API gravity of 50.6; an aniline point of 146; acid wash aniline point of 151; an avcjrage molecular weight of 139; a boiling range of 308-366 F. with a 50% ASTM distillation point of 328 1 and a 90% point of 341 Example 4.The hydrocarbon hydroperoxide mixtures obtained in accordance with Example 3 above were treated with acid at temperatures of about 60-80 F. as indicated in the following Table III:

TABLE III Results of acid catalyzed condensation of peroridized hydrocarbons Oxygen Factor Corrected ON Hydroperoxide From Before After 2.5% 10% n-Decane, 75% Hz S04, 0.25 lb./

gal 561 107 7.0 11.5 n-Decane, 36% I161, 561 16 3.0 4.4 n-Decane, 48% HBr, 25%. 561 29 2.3 4. 6 Octene-l, 75% H2804, 0.25 1b.]

gal 902 372 4 0 9.8 Decene-l, 75% H2304, 0.25 lb./

gal 504 123 3.0 7. 8 Decene-l, 75% B280 gal 375 67 l. 1 6. 2 Ethylcyclohexane, 75% H 80 0251b. a1 1; 250 278 5.8 12.3 Ethylbeuzene, 75% H 8 04. 0.25

lbJgal l, 868 905 4. 2 9. 7 o-Xylene, 75% H2804, 0.25 11).]

gal 564 45 1.0 2.9 Tech. Monoamylbenzene, 75%

H130 0.25 1b./gal 353 85 1.3 3.1 Petroleum distillate, 75%

H 804. 0.25 lb./gal 800 100 4. 9 9. 8

I Same distillate as in Tablell.

Example 5.'700 c. c. of a petroleum distillate, which after washing with one-half pound of 96% sulfuric acid per gallon, was relatively free from asphaltic and resinous materials and was composed of about 41% parafiins, 47% naphthenes and 12% aromatic ring compounds, had a gravity of 464 A. P. I. boiled within the range of 310 F. and 364 F. and had a cetane number of about 35, was oxidized in a treater similar to oxidizer 4 shown in the drawing.

In this oxidation, the oil plus 18 c. c. of feed stock from a. previous run was air-blown for three hours at a temperature of about 300 F. and at a rate of two volumes of air per volume of oil per minute. The hydroperoxide-containing oil from this operation had an oxygen factor of 801 and octane number of 77. This product was washed with a ten per cent excess of 10% aqueous caustic to give a product having a neutralization number of 1. This neutralized hydroperoxide-containing oil was then treated with one-quarter pound of 75% sulfuric acid per gallon of oil added in five dumps over a period of fifteen minutes at a temperature of about 75 F. to convert the hydroperoxides to di-hydrocarbon peroxides. The product had an oxygen factor of 98, a neutralization number of 0.04, and a cetane number of 65.5, and constituted a highly desirable Diesel motor fuel for use as such or in a blend with other lower quality components. For example, when 5% of this partially oxidized acid treated product was added to an untreated Diesel fuel base from waxy California crudes and having a cetane number of 42, the cetane number of the blended fuel was raised to 47.7.

The foregoing example covering oxidation and acid treating steps illustrates the practice of the invention by a procedure wherein a concentrating step is not employed.

Example 6.The di-hydrocarbon peroxide-containing product resulting from acid treatment in Example 5 is distilled at 5 mm. of mercury pressure and 130 F. until of its volume has been removed. The vaporized portion had an oxygen factor of 13 and a neutralization number of less than 0.005, while the concentrate remaining in the still had an oxygen factor of 670 and a neutralization number of 0.033. Three per cent of this concentrated product was added to an untreated Diesel base fuel derived from waxy California crude and boiling within the range of 340 F. to 576 F. and having a cetane number of 41.1. The cetane number of this blended fuel after sixteen days of storage was 52.4.

Example 7:-700 c. c. of the same acid washed petroleum distillate feed as used in Example 5 was fed to the oxidizing reactor. 18 c. c. of feed stock was added and the mixture air-blown for three hours at 300 F. using an air rate of two volumes per volume of oil per minute. The resulting product had an oxygen factor of 1175 and neutralization number of 11. This hydroperoxide-containing product was treated with onequarter pound of 75% sulfuric acid per gallon The resultant 'di-hydrocarbon peroxide-containing product was distilled "at-5 mm. of mercury-pressure and 122 F. until 'jtwentyper cent of the original volume remained as a residue r concentrate. This remaining concentrate of di-hydrocarbon peroxides had an oxygen factor of 740 andaneutralization num- "ber' of 0.1. Three per cent of this concentrated product'wasblended with an untreated Diesel base derived from waxy California crude and having a cetane number of 41.1. After sixteen days storage this blend showed a cetane number of 50.9 'or an increase in cetane number of 9.8.

Example 8.-'A petroleum distillate feed similar to that used in Example wasoxidized and caustic washedasoutlined in Example 5. 17% of this hydroperoxide-containing product "was blended with an automotive Diesel fuel boiling within the range of 308 F. to 578 1F. andhav- 'in'g achart cetane number of 42'. This blended stock having an oxygen factor of 153 was then treated with one-quarter pound of 93% acid per gallon of stock at about 70 F. to convert in si'tu the hydroperoxides to di-hydrocarbon peroxides.

The finished stock had an oxygen factor of.2.2 and a cetane number of 50.5.

.Example 9.--A petroleum distillate similar to that .usedin Example. 5 was. air-blown andcauslticwashed as in Example 5 and thereafter exhibited an oxygen factor of 839 and a neutralization number of .12. This product was distilled at 330 mm. pressure and a temperature under 200 F. to separate the higher boiling'fraction as a concentrate of hydroperoxides constituting: about 12.15% .ofthe original liquid volume.

Two per cent of this concentrated product having an oxygen factor of 6240 was then blended in a refined distillate derivedfrom California "crude and boiling within therangeof 388 F. to 656 F. and having a cetane number of el. After fOItY-Eight-ITOUIS storage, this blend had a cetane. number of 4.8.2.

Example 10.--A petroleum distillate similar .to that employed in Example5 was oxidized, neu- .tralized, and concentrated as inExample 9. One portion of the hydroperoxide concentrate was treated with one-quarter pound of 75% sulfuric acid per gallon at 77 F. for fifteen minutes and a second portion was treated with one and onehalf pounds of 75% sulfuric acid per gallon at 77 F. for twenty minutes. The two products had oxygen factors of 3920 and 840, respectively. Two per cent of each of these products was added to an automotive base fuel having a cetane number of 40.9. After ninety-six hours of storage the blended fuels had cetane numbers of 49.1 and 50.8, respectively.

Example 11.--The storage stability in Diesel fuel of a hydroperoxide-containing mixture derived from the petroleum distillate of Example 6 and concentrated as in Example 6 was compared with di-hydrocarbon peroxide-containing mixture obtained by treatment of this hydroperoxide mixture with 1 /2 lb. of 75% sulfuric acid per gallon in a manner similar to that described in Example 7. Each of these products was added in amounts of 2% to an automotive Diesel base fuel derived from southern California crude and having a cetane number of 36. The cetane numbers creamer the resultant blends at various times are in'dicated in the following Table IV:

TABLE IV Oxygen. Fay Octane Improvement Blending Agent tor of Blen lmg Agent 15 min. 48hrs. 96 hrs.

Hydroperoxide stock e, 240 12 7 6 Di-hydrocarbon peroxide 'stock 840 11 L11 10 The "data of 'the above table illustrates "the greater storage stability of "the (ii-hydrocarbon peroxides. Likewise, the di-hydrocarbon perioxi'deshaving higher molecular weight hydrocarbon radicals of above 8'carbon atoms have 'beenfound tobesuperior in storage in the presence of moisture or water to lower dialkyl peroxides .or' 'hydroperoxides.

"Example 1'2.'To compare corrosivity of the hydroperoxide stock and peroxide stock mentioned in'Example'll iabove, lead corrosion tests were carried .out "by immersing a lead strip 1%" /2""X 1-%"'in a beaker of the sample maintainedlfor24. hours'at about 225 F., and the loss 'in weight noted. The results showing that the hydroperoxide stock is considerably more corrosive than the iii-hydrocarbon peroxide 'stoclgare given'in'the following Table V:

As' indicated"hereinabove;the products of the present invention-,- particularly the peroxides derivedfrom higher molecular weight-saturated hydrocarbons,-'such as. paraffins and naphthenes having above 6 carbon atoms and especially 8 to 12 carbon atoms, maybe used in concentrated form (1. e., l0 to 60% concentration) as excellent Dlesel fuel additives for increasing the cetane number thereof. Such concentrated dihydrocarbon peroxides may be incorporated in Diesel fuel in amounts between about 0.2% and 25% of the base fuel, desirably between about 0.75% and 15%, and especially about 1% to 8% of the base fuel. While ordinarily the base fuel is preferably substantially free from large proportions of aromatic ring compounds (i. e., the base fuel should contain less than 20% and especially below 10% of aromatics), it is sometimes satisfactory to use a base fuel having higher aromatic contents, such as 20% to 40% and to impart the desired ignition qualities thereto by addition of the (ii-hydrocarbon peroxides, especially those derived from saturated hydrocarbons having about 8 to 12 carbon atoms. Higher aromatic contents may be used in some cases up to aromatics, since the products of the present invention give the same effect in various fuel of the same cetane number. Where the original hydrocarbon used to form the hydroperoxide or the hydrocarbon diluent for the hydroperoxide is a suitable Diesel fuel, the product resulting from acid treatment may be used without concentration the whole or major portion of the Diesel fuel.

hydrocarbon peroxides for use as ignition accelerators, the products, in unconcentrated, concentrated, or substantially pure form, may be beneficially used in other applications. For example, the products may be employed as vulcanization accelerators, polymerization catalysts and initiators, such as in the polymerization of polymerizable unsaturated compounds, including both the conjugated and unconjugated unsaturated polymerizable compounds, etc. For the latter purpose, the di-hydrocarbon peroxides derived from aromatic ring compounds are sometimes most suitable; for example, aromatic hydroperoxides obtained such as from air-blowing aromatic compounds, such as toluene, xylene, etc., may be converted to peroxide by the acid treatment of the present process.

The products may, in general, be used as catalysts for various chemical reactions or as intermediates in organic synthesis. Likewise, these products may be used as basic chemicals for forming desired derivatives thereof. Also, the products as such or derivatives thereof may be employed as insecticides, gum solvents, etc.

The present application is a continuation-inpart of our co-pending application, Serial No. 666,701, filed May 2, 1946.

We claim:

1. The process of autocondensing organo hydroperoxide to di-organo peroxide, wherein said organo group consists essentially of a hydrocarbon group, which comprises contacting said organo .hydroperoxide with strong acid as the sole reactants, under the following mild conditions: the contact time being less than 90 minutes, the temperature being below about 95 F., the acid having a dissociation constant of at least 10- and said acid being present in an amount and of suflicient concentration to autocondense a substantial proportion of said organo hydroperoxide to di-organo peroxide.

2. The process of claim 1 wherein said hydroperoxide reactant is dissolved in a substantially inert diluent.

3. An improved method of producing a di-hydrocarbon peroxide comprising bringing into 29 contact for less than 90 minutes and at a tam perature below 95 F., a hydrocarbon hydroperoxide and an acid as the sole reactants, said acid having a dissociation constant of at least 10 and being present in sufficient amount and concentration to autocondense a substantial proportion of said hydroperoxide to a (ii-hydrocarbon peroxide.

4. The process of claim 3, wherein said hydroperoxide is a saturated hydrocarbon peroxide.

5. The process of claim 3, wherein said hydroperoxide contains at least 6 carbon atoms.

6. The process of claim 3, wherein said hydroperoxide is a tertiary hydrocarbon peroxide.

7. The process of claim 3, wherein said hydroperoxide is a secondary hydrocarbon peroxide.

8. The process of claim 3, wherein ratio of acid to hydroperoxide is about 0.1 to about 1.0 mol of cid per mol of hydroperoxide.

9. The process of claim 3, wherein ratio of acid to hydroperoxide is about 0.3 to 0.5 mol of acid per mol of hydroperoxide.

10. The process of claim 3, wherein said acid is a mineral acid.

11. The process of claim 3, wherein said acid is sulfuric acid.

12. The process of claim 3, wherein said acid is to 98% aqueous acid.

13. The process of autocondensing a hydrocarbon hydroperoxide to a di-hydrocarbon peroxide which comprises contacting said hydrocarbon hydroperoxide for less than 90 minutes with a 50 to 98% aqueous solution of a mineral acid having a dissociation constant of at least 10' at a temperature of 50 to F. with an acid to hydroperoxide ratio of about 0.1 to 1.5 mols of acid per mol of hydroperoxide, wherein said hydroperoxide and acid are the sole reactants.

GEORGE H. DENISON, JR. JOHN E. HANSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,403,758 Rust et al July 9, 1946 2,403,771 Vaughn et a1 July 9, 1946 2,403,772 Vaughn et al July 9, 1946 

1. THE PROCESS OF AUTOCONDENSING ORGANO HYDROPEROXIDE TO DI-ORANGO PEROXIDE, WHEREIN SAID ORGANO GROUP CONSISTS ESSENTIALLY OF A HYDROCARBON HYDROPEROXIDE WITH STRONG ACID AS THE SOLE REACTANTS, UNDER THE FOLLOWING MILD CONDITIONS: THE CONTACT TIME BEING LESS THAN 90 MIN- 